Refrigerator car with fan and brine circulating system



T. M. ELFVING Feb. 9, 1954 REFRIGERATOR CAR WITH FAN AND BRINECIRCULATING sYsTr-:M

Filed March so, 1951 2 Shee'hs--SheefI l INVENTOR. THORE M. E/ FV//VGFeb. 9, 1954 T M, ELFVlNG i 2,668,421

REFRIGERATOR CAR WITH FAN AND BRINE CIRCULATING SYSTEM Filed March 50,1951 2 Sheets-Sheet 2 z l f l/l//l/z/l/ 1/ 11i/,fl /////,l

IVENTOR.

Patented Feb. 9, 1954 gieizfl REFBJQERATOR GAR Wirn v.FAN .AND .BRINEEen@ @Eltrilig een AAS Mateo., C

Appliootionmamhfan, 1951, serial-No. `218,350

The Apresent .innentionnrelates .to railroamrefrigeratorcarsusing ice`or a-.mixtureof iceend saltasrefrigerant. It .hasiforits purpose,Stopwvide a .refrigerator ...can ,which can maintain .a constant .lolw.temperature -`inclepenfilent.0f the amount of -iee andsalt in.fthe-.ice bunkers ,and independent ofthe .carbeingin motion tir-.not

According .to .the.,.invention .the temperature inthe car @an .bel-thermostatically ...regulated .as ifothecar was .provided .with.mechanical refrigeration. g Like ,presentrefrigeratornar.lhelwestYtemperature.obtainable in .a .ear .,willtbede.- pendent-.upon-.thetemperatureof theieland salt mixture., orothereirigerant inthe.l icebunkers, but in other respectsthepresent .inventiomeliininates many. ofthe .weaknesses foundinrailroadrefrigerator oarsofV the,presentce-bunKer type- Arefrigeratorcaroaccording.tothepresentinvention .can `use .either eend.. ice:l bunkers .Qrfcrerhead.ice ;bunkers..or..both. .-As ,an Lexernplt.,.the invention -.wi1l.b.e.described in, connection e-Wfh the -accompanyingidrawings as...app1iedto ...a 12.6- frigator .car Yof the. .end -.ice .;b.i inlier..type.

Inthe drawings:

vFigure Q1 .shows I.a longitudinal... section through one-half. .of `re,1 refrigerator .caraccording 1.1.10 @the invention, and

Figure 2 shows a cross section View Qfrtkietar as.-.sho.wn inFigure 1.

.-In :these draw-mesa conventional. refigelatcr car'. is,shownosocmposed. of. wneelsepresentcd by l,..underframe 2,.in.s.u.lated4ffioor t? end. walls e4,- .insulatedgside.walls-...inn ceiling i6.r`Said.v refrigerator car@ indicated .a hconventional...structiiral.'.hiilkhead a forming aspace.inetherendeof said .ca-r; known totheitrade as anlendoiceibunkerg 8. Thefwalls of A.said icehunker.f..are\formedfbyethe L.car .end linings, side lining:l9,.fand.structuralibulkhead 1. 'The ceilingis .formedmbyfthecar,ceilingfM andthe/floor is ormedhyaooor panrtZrM/'hich isprovidedwithradrain :113. through a watenseal M. '.Also indicated larehatch.,.openings [5,.and floor.. racks .|i6,.a1l voiazvhich.wemelt-known.

.iInside .of said ice .bunker .-thereis ...constructed anzice tank Il.directly connected.withztliefhatcl'i` openings l5 insuchiawaygthatlan-air passageol is ...providedover.:the.,ioezitankfaround.said,openings. -The` ice .tankoisfsoiarrangedias .atol provide ani air-space le `and. .an airochannelfil)..betii'zeen the-ice .tank vandi-,theocar .structureat Alool,li...the`side and end walls. yFIheaieetank..A I Lis.water-ztight except for theopenings ..21 Y@for f.. brine .'overow. The iceitankisi-supported by Y-the-structuralabulkhead-#Land across beainZ. 11n-tiledcetank-Lis.4

' theicegrate.. At thecenterof thehcarthetloettom of. tneice tankis.proridednitha-ri1tni valve 2E -for.emptying.and cleaning tlietank.

`Asseen fromv v,the .abus/...e .siescrinjiiQn .flle QC tank .u is,surroundedon all...sideswith arassages through .which .air .can beCirclllfifdt .159.1 cooling-bycontactivth the. coldsdes Qf.. .htnllk-Thisotersa considerablecoolingapaictyiwhik however, nis `rvery .much.increased :by ,the -blili circulating .system added 4, to the bunker.iiQQOrdf ing .to .the invention. .Such a .crculatingwtcm can .be.provided .with ,cooling .Sur-fa .large enough .to .obtain the .total.cooling ,Capacity needed for .a car .of this type. The brine .iscirculated Joymeansof amotor ,driven pump 12J which takes .the ,brine...throueh..th.e ...pip .2.18 fromthe brine spacef underncath..thc. c.eg

Brine. is .forced fromjtherpump.throngllfflhpip h eat .exchange .unit.19 .consieting of yertiqally arranged;.horizont.al-pipes,.proyidedWitnnns. and located inanar `.circulation flue ,en adjacen to thestructureobulkhead Land separatedirgnisaid h u1khead..by Y.a wall or.baffle .31 .extendingjironi thesh'ottomwither.bnlkheadmeinbere Y l of.theiippermost horzcntalnnpine- .A A ls point theairrflue Seann .thespaceetween the structural,bulkheadmemners commu otherside. ofetheair flue3.0 :is 10min.. by na. ...wooden lining .3 2 ...Which extends fr bottom;ot nthe.Joulkheadirneiii.IQSJFS. lqthfi ing..33. ...Theliin 4pipesareinstries and tm lorgne .will g'rarjnally raise in temperature .when.11%- ing through .thisair ...cooling system. Thbliile iS brought-back.to the ...ige tank ftliloilg 1.1 .ilhollli 34. .Thispipe,conductsetnewarm brine to .line top ofhtloetank @between `-.the hatch...openings Iand leads.. across ther-tank etc' the outlet spray ...pipe35, from -whicnthe-brine issprayed oizerthei an-salt mixture-in thetank. v.'lhe=,..`ri. eated brine melts `somelof the ..ice,.additional'saltis dissolved`,andithe circulation..is..repeated.

fTh'e air isj accbrdngl to .theiinventom..irculatedlaroundthetotalcoolngystemhyemcens of.,electric..fans;3.i.located .1.1L .hQlQSi 31,1238. fm housing .1:33. -.'1`..h.e .air.circulation between ,eine commodityspaceiofthe carena-,the .COQlillSYS- temidescribed .aboye-.is carried..oi its.inthe sfollowing LWayBelow .the:;load;inxthe car thetairmis cifrciilateiiiny:thespac.e...between rthefflocr .edck

` 3'82'andotheaocr-rack.. t6.;andislpulledzhyetheffan into the coolingsystem at the bottom of the bulkhead. The air now is divided in threeseparate Ways. One part of the air coming from the commodity will go theshortest way through the air flue 30' passing over the brine circulatingcoil system. This lowers the temperature of the air before it reachesthe upper part of the vertical flue where the fans force it out into thecommodity space again. Another portion of the air flow goes between thebulkhead structural members between the ice tank l1 and the wall 3|.large cooling surfaces the air flow through this As this passage of theair does not offer Y area is restricted by a restriction member 39.

This member 3B does not prevent air circulation by free convection incase the fans are not operating. The remaining portion of air goes underthe ice tank and passes around the remaining three sides of the tank upto the top of the bunker, from there to the fans and out over the loadagain. All three passages described above offer a certain cooling eiectto the car, but it will be shown in the following description that themajor portion of the necessary refrigerating capacity will be providedby the brine circulating nn pipe system. This system'will maintain thesame brine temperature, as long as any ice remains in the eutectic brinein the tank. It is therefore capable of maintaining a reasonablyconstant rerigerating capacity as long as the brine pump and the fansare operating.

e As shown in Figure 2 of the drawings, the

brine circulating system connected` with the ice tank is seen from thecar after removing the wall 32. I2 is the floor pan with the drains I3and water seals I4. The brine circulating pump 2l with the motor 40 andthe inlet pipe 28 is located between two bulkhead structural members inan opening in the wall 3i within the bulkhead sections and the air flue30. The pump is therefore readily accessible from inside the car throughan inspection opening in the wall 32. The pump is located underneath then pipe system and the. whole system will drain itself through the pump,

and the inlet pipe 28 when the brine in the ice tank is drained offthrough the cut off valve 2B.

shown in Figure 1. This automatic draining oi the cooling coil systemand the pump is very important for the reliable operation of the brinecirculation as sedimentation inside the pipe system or inside the pumpshould be avoided. The

heat exchange unit 2s is secured inside the airflue by means of woodenmembers 4t which are bolted to the bulkhead structural members. Thesemembers 4i also serve as'stringers for securing the plywood wall 32. InFigure 2 are also shown the fans 3S located in the openings 31 as wellas the outlet pipe 34 leading from the fin pipe system to the spray pipe35 which runs practically the full width of the tank. The upper layer ofthe ice and salt mixture in the tank is thereby contacted by thecomparatively warm brine coming from the cooling coil system.

The refrigeration capacity needed for a heavily insulated lowtemperature car is usually estimated to be approximately 20,000 B. t.u.s/hour. As previously stated it is possible in a refrigerated car,according to the present invention, to provide the brine circulatingsystem added to the bunker with cooling surfaces large enough to takecare of this needed refrigerating capacity. This is accomplished -byusing iin pipes and by balancing the brine and air circulation in orderthat a correspondingly large heat flow takes place from the air to thefin'pipe system. and from the 75. placed in a suitable position in thecommodity n pipe system to the brine, and finally to the ice and saltmixture in the ice tank. The refrigerating capacity to the airrepresented by the surface of the ice tank itself may serve as a marginof safety for extreme conditions. A refrigerator car according to theinvention should have the following approximate data as far as thecooling system is concerned: The ice tank capacity should be about thesame as for conventional cars of the end bunker type, that isapproximately 12,000 pounds of ice plus 30 per cent salt by weight.Because of the ability of the invention to maintain full refrigeratingcapacity until all the ice is melted this amount of ice will besuflicient for approximately 60 hours of operation. With the aboveproportions of ice and salt it will be possible to obtain a temperaturein the ice tank of about -5 degrees Fahrenheit, which temperature willbe maintained in the brine entering the brine pump as long as any ice isleft. It is assumed that an average temperature difference of 10 degreesFahrenheit between the coil system surface and the circulating air inthe air flue is obtained and it can also be assumed that the heattransmission coeiiicient between the fin pipes and the air will be 5 B.t. uis/square oot/hounper degree, F., which corresponds to the airvelocity obtained with a fan capacity of 3000 C. F. M. or more. We ndthen that the cooling surface needed for transferring 20,000 B. t. u.sper hour is about 400 square feet. Approximately half of this surface isobtained with a nn pipe system as shown in Figure 2 which is composed o3A" pipes provided with suitable fins.

If a brine temperature rise of 3o F. is allowed during the passage ofthe brine through the vcoil system it takes the circulation of 400gallons of brine per hour to deliver a refrigeration capacity of 10,000B. t. u.s which gives a brine velocity inside the pipes of approximately300 feet per minute. The pump and motor capacity should be chosenaccording to this requirement. With the above dimensions of the coolingcoil system together with the cooling capacity of the tank itself itshould be possible to maintain a temperature in the car of 5 F'. orlower under all conditions.

The brine pumps and the fans, as employed according to the presentinvention, are driven by electric motors which are connected by thecable 42 with an electric generator driven by an internal combustionengine. Figure 2 shows the electric motor for the brine pump 21, andFigure 1 shows the motor 43 for the fan 36. Figure l also shows theengine-generator unit M as located on a suspended platform 45 which ishung between the underframe cross tie d6 and the underframe cross beam41. The enginegenerator unit is provided with an intersection door 48having grills 49 for air circulation. The engine has a fuel tank 50 witha, capacity large enough for driving the generator at least 10 days,while the car is in transit across the country. A generator forsupplying fan and pump motors, according to the invention, withelectricity of a suitable voltage has only to produce between 1 and 2kilowatts, and an internal combustion engine of 2 to 4 horsepower issufficient for driving the generator. This engine should be of theair-cooled heavy duty type and providedv with a starting battery,starting motor, and an automatic starting control unit for thermostaticoperation. A selective thermostatic control 5I reageer:

mun determined bytrfete' h erant in the ice bunkers. en usingiceands'al't with an eute'ctic temperature of about* "-155 kli'. theIiinizriding'tenjlpe'ratt'lre` in the car will probably be 2 F. or*slightly below. 4The brine tand air circulating system jcan vbe placedin 'operation a's "scoh `as 'thejcar has been ticed, thereby reducingthe normal precooling time considerably.

l:refrifgerator 'car cooling "system, l'according to the invention, issuperior to jmechanical'r ef rirge1jation 'fvvith a `compressor unitinthe Yrespect 'that ice and salt inthe lice 'bunkers oiersfa'soirce `ofrefrigeration which isfavailable even iiv the'jc'om'- bustionfen'ginejrftlef'generator or other mechanicaltpa'rtshf 'thefsystemfsh'ould fail.The refrig eration capacity of this system, when 'the brine pump' or the1f ans 'arenot operating, 'is small 'come pared with fthe refrigerationcapacity when the cooling jfcoil system isw'orking according 'to theabv'e description ,AI-Iowever, "theV refrigeration with natural'convectic'nfoi the airis 'sufficient vrin rho'stcases to prevent damagetothe commodity. The Vair :Flow "around 'thebnker system, when the 'fansare `standing "'still, will 'be in `reverse to the air Eiow'described'above. Gravity "dinierence will cause theairtoente'rth'es'ystem through the fan lholes and `-flow"do'wriwa'rdsaround thetank between j the bulkhead structural members and through theairiueforfthe'n' pipe System. "Rest'riotions'in the `air passageswill'h'ave'less'efect on `slow 'moving Aair than "on forced air 'and abunker system, according lito `the invention, fwill therefore oier equalrefrigeration, when "fans `rid pump are not loperatir'rg, toirdiaryendbunker'car's now genral use.

A-brine circulatin'gf'cooling system, according tothe invention,canbe'lccated'orfarranged in I'a'riy diierent ways.l IForced brinecirculation combined with forcedfaircirculatifon makes it possible toarrange l'the -iin "pipe "co'oling is'ys` tem' almost 'anywhere in thecar. 'A` verticaln pipe system similar to that 'desc ribed"above'fma37be 'placed' in 'afw'all flue behind :the' bunker "or at the sidewalls.It is `also possible to arr ng'e'th'e brine circulating system along the"ceiling of fthe oar,` above `the loading'spac'ead 'between thebulkheads. l

The cooling"'coilsystemiadd'd to" the rbnlnfer in order to'inoreasetherefrigeratofcapacity"'of the ca r, according to the invention, can"A'c beof'the s'elf -circulating typegthat is:a'himetically'fsealed heattransfe1""s'ystemfus`" g'"a' volatile 'refrigerant s'uclias ammonia' forn. In"thi's'casea brine pump would not be"reqird,`a1d"th`e'enginegenerator unit has' onlyv to supply' electricity to the I'fan forcirculating 'air around" 'the preferably such a 1h ermeti'callyl sealedcirculating'sys'ternas Wellasa'round theice tinker, l

LA@brine-fcirculatngssyste fonc'ooling'"tleair staff-tie an' ne!ature'orf the refrig'- can faccoin'g 'te' 'the invention I* aise tecih-the spray lor wet surfaceftype, inwhich case the brine i's'pmpedfrom the bottom of the ice tank upto a spray pipe located in a verticalair fluev through which air is circulated. After leaving Vthe spray pipethe brine may-either Yfall 'in small drops throughth'e air lor `drizzleIover 'preferably-"corrugated surfaces Iover which the 'air is lpass-ingwhile being lcooled. The pump brine maybe divided "in two Ways, one partbeingspra-yedover the toplay'er of ice and "salt 'in the ice tank, :theother part passing the aircooling iiue back to the bottom or 'lower-partcf theicet'ank.

Thegenerator lu'sed'fo'r 'supplyingelectric power to the pumpsand/orfans used inthe V'cooling system, according tofthe invention, can alsobedriven 'from the wheels Acf `the car in which' case the generator Ahasto be provided with a storage battery A'for A'operating `the pumpsand/or "fans when-thecai` is standing still. The thermostat has in this'alt'ernativeonly to operate fa 'switch'in theel'ectric circuit.

"Wl1il`ehave, 'for 'the 'sa-ke'of lclearness and in order Ato-disclosetheinvention sothat `the same can -r`be 'readily understood, described"and"`illus` trated specic devices and arrangements, 'I `desire'to havelit understood that this inventions not llimited to the 'specic meansdisclosed, but

may be Aembodied in -other'ways thatiwill "suggest themselves Itolpersons skilled in the art. It is believed that this invention is'newand all such changes ascome Withinthe'scope of the` appended' claimgareto be considered-'as partefthisfinven-l tion.

4'Having thus described my invention, what 'I claim and desire toisecureby Letters EJPatent :is:

l. In a refrigerated-railway canhavinglannsulated lading accommodatingjspace; the combination ofl 'anice and-brine "accommodating tank mountedwithin sai'dcar atl one V4endend spaced from `the top, -bottoinyend andside "walls `thereof -for -free passage of air therearound,"a-baiiiedisposed Lvertically'and transversely-of saidcar body -and terminating'-in spaced *relation 'with the fiioor andv ceilingy of the oar to-provide "anair' passa'sway7i adjacent vthe inward `side-of *said icevtank, aheatwexchangelunit mounted' atthe` other side fof-said baffle andwithin 'the Kupper and lower limits thereof, a brine lpump for'circulating brine v"from the bottom'of "said tank' through Isaidheatexchange'unit 'and discharging' same as-a sprayatithe top"of"saidicetank, an insulating end 'wall mounted `in `inwardly spaced relationwith respect to'said heater(- change unitwhich denes` the klimits ofthef'ladingspace and provides an aircirculating passageway throughwhichair will circulate over said heat exchange unit,'said end VWallbeing disposed 'withfitsv bottom edge in spaced Hrelation with floor ofthe car and having ran"apertme locatedabove vsaidheat exchange junit,fan electricI fan mounted in the'aperture'insaid'end Walll cooperating'relation 'with 'said 'baflie'ior maintainingr a' forced circulation ofairfrorn thelading space Vabout-said ice tank'and .over said' heat,

exchangeiunit, and means at' the lower .edge of saidbatlieffor directingthemajor portion of the fan circulatedfair over said v'heatexchangeunit.

2. vIna'refrigerated'railway car'having an insulated ladingaccommodating space; the-com bination of Aan ice and "brineaccommodating tankm'ounted at one end "Within said car and spacedfrointhetop, bottomfend and vside Vwal-ls thereofto'provide'for'a'freeycirculation of air 7 therearound, a vertically disposed bailleextending transversely of said car body and spaced from the noor andceiling to provide an air passageway adjacent the inner side of said icetank, a finned pipe heat exchange unit mounted at the side of saidbaffle remote from said tank, a brine circulating pump for circulatingbrine from the bottom of said ice tank through said heat exchanger anddischarging same as a spray over the ice in said ice tank, a heatinsulating end wall mounted within said car body and inwardly withrespect to said heat exchange unit to provide a confined space throughwhich air will circulate over the iin pipes of said heat exchange unit,said end wall being disposed in spaced relation with floor of the carand having an aperture above said heat exchange unit, an air circulatingfan mounted in cooperating relation with said bane and the aperture ofsaid end wall for circulating air from the lading space of said carabout said ice tank and over said heat exchange unit, and means forregulating the now of air about said ice tank, the arrangement beingsuch that the major portion of said circulating air will be passed oversaid heat exchange unit when said fan is operating.

3. In a refrigerated railway car having an insulated ladingaccommodating space, the cornbination of an ice and brine accommodatingtank mounted within said car at one end and spaced from the top, bottom,end and side walls thereof for free passage of air therearound, a bailleextending transversely of said car body in spaced relation with saidtank and spaced from the floor and ceiling of the car to provide an aircirculating passageway about said ice tank, an insulating end wallmounted in inwardly spaced relation with respect to said baffle whichdenes the limits of the lading space and provides an air circulatingpassageway remote from and independent of the passageway about said iceand brine tank, said insulating end wall being disposed with its bottomedge in spaced relation with iloor of the car and having an aperture atits upper edge, an electric fan mounted in the aperture in said endwall, a heat exchange unit mounted in said latter air circulatingpassageway, a brine pump for circulating brine from the bottom of saidtank through said heat exchange unit and discharging same as a spray atthe top of said ice tank, and means at the lower edge of said baffle forlimiting the flow of fan circulated air about said ice tank when saidfan is operating.

4. In a refrigerated railway car having an insulated ladingaccommodating space, the combination of a bulkhead having an opening atits top communicating with the interior of the car and forming a chamberfor an ice and brine accommodating tank at the end of the car, an iceand brine tank mounted within said chamber in spaced relation from thetop, bottom and side wall of said chamber for the free passage of airtherearound, a vertical wall disposed in inwardly spaced relation withsaid bulkhead and providing vertical air circulating passageway, acirculating brine heat exchange unit mounted in said air passageway anddisposed between the upper and lower limits thereof, a brine circulatingpump for maintaining a circulation of brine downwardly through said heatexchange unit and discharging said brine as a spray over the ice in saidice and brine accommodating tank, and means for maintaining a forcedcirculation of air upwardly through said air circulating passageway fromthe bottom to the top of said lada ing space of the car, whereby the aircirculating over said heat exchange unit will ow in countercurrentrelationship with the brine circulated through said heat exchange.

5. In a refrigerated railway oar having an insulated ladingaccommodating space, the combination of a bulkhead having an opening atits top communicating with the interior of the car and forming a chamberfor an ice and brine accommodating tank at the end of the car, an iceand brine tank mounted within said chamber in spaced relation from thetop, bottom and side wall of said chamber for the free passage of airtherearound, a vertical wall disposed in inwardly spaced relation withsaid bulkhead and providing vertical air circulating passageway, acirculating brine heat exchange unit mounted in said air passageway anddisposed between the upper and lower limits thereof, a brine circulatingpump for maintaining a circulation of brine downwardly through said heatexchange unit and discharging said brine as a spray over the ice in saidice and brine accommodating tank, and means for maintaining a forcedcirculation of air upwardly through said air circulating passageway fromthe bottom to the top of said lading space of the car, whereby the aircirculating over said heat exchange unit will flow in countercurrentrelationship with the brine circulated through said heat exchange, saidair circulating means being disposed and arranged so as to not interferewith a free convection circulation of air around said ice and brine tankand over said heat exchanger unit when said air circulating means is notin operation.

6. In a refrigerated railway car having an insulated ladingaccommodating space, the combination of a bulkhead having an aperture atits top communicating with the interior of the car and forming a chamberfor an ice and brine accommodating tank at the end of the car, an iceand brine tank mounted within said chamber in spaced relation from thetop, bottom and side wall of said chamber for the free passage of airtherearound, a vertical wall disposed in spaced relation with saidbulkhead and providing narrow air circulating passageway extendingthroughout the width of the car, a circulating brine heat exchange unithaving horizontally extending nned tubes mounted in said air passagewayand occupying the space between the sides and the upper and lower limitsof said passageway, brine circulating pump for maintaining a highvelocity circulation of brine downwardly through said heat 'exchangeunit and discharging said brine as a spray over the ice in said ice andbrine accommodating tank, and means for maintaining a forced upwardcirculation of air through said air circulating passageway, whereby theair circulating through said passageway and over said heat exchange unitwill flow in countercurrent relationship with the brine circulatedthrough the iinned tubes of said heat exchange unit.

'7. In a refrigerated railway car having an insulated ladingaccommodating space, the combination of a bulkhead open at its top andforming a refrigeration medium accommodating chamber in communicationwith the interior of the car, a metallic ice and brine tank mounted insaid chamber in spaced relation with the top, bottom, end and side wallsof the car, a vertical wall extending transversely of said car body inspaced relation with said bulkhead and forming an air passagewaythroughout the width of the car, a heat exchange unit mounted betweensaid bulkhead and said vertical wall and within the upper and lowerlimits of said vertical wall, a brine circulating pump havingconnections for withdrawing brine from the bottom of said ice tank andcirculating said brine downward through said heat exchange unit andreturning said brine as a spray at the top of said ice and brine tank,said vertical wall being terminated short of the oor of the car andhaving an aperture above said heat exchange unit, and an electric fanmounted in cooperating relation with said bulkhead and the aperture insaid vertical wall for maintaining a forced circulation of air from thelading space of said car about said ice and brine tank and through saidvertical air passafeway in countercurrent relation with respect to theow of brine through said heat exchange unit.

8. In a refrigerated railway car having an insulated ladingaccommodating space, the combination of a bulkhead open at its top andforming a refrigeration medium accommodating chamber in communicationwith the interior of the car, a metallic ice and brine tank mounted insaid chamber in spaced relation with the top, bottom, end and said wallsof the car, a vertical wall extending transversely of said car body inspaced relation with said bulkhead and forming an air passagewaythroughout the Width of the car, a heat exchange unit mounted betweensaid bulkhead and said vertical wall and within the upper and lowerlimits of said vertical wall, a brine circulating pump havingconnections for withdrawing brine from the bottom of said ice tank andcirculating said brine downward through said heat exchange unit andreturning said brine as a spray at the top of said ice and brine tank,said vertical wall being terminated short of the floor of the car andhaving an aperture above said heat exchange unit, and anelectric fanmounted in cooperating relation with said bulkhead and the aperture insaid vertical wall for maintaining a forced circulation of air from thelading space of said car about said ice and brine tank and through saidvertical air passageway in countercurrent relation with respect to theflow of brine through said heat exchange unit, said air circulatingmeans being disposed and arranged so as to not interfere with a freeconvection circulation of'air around said ice and brine tank and oversaid heat exchanger unit when said air circulating means is not inoperation.

9. The improvement in a refrigerated railway car having an ice bunker atone end which comprises, a metallic tank within said bunker and spacedfrom top, bottom and side walls thereof to permit a free circulation ofair thereabout, said metallic tank being charged with an eutecticmixture of ice and salt, a circulating brine heat exchange unit disposedinwardly and adjacent said metallic tank, a vertical and transverselyextending partition at each side of said heat exchange unit forming twopaths for the circulation of air from within the lading space of saidcar, one such circulation being around and about said metallic tank andthe other over and about said heat exchange unit, pump means forcirculating brine from the bottom of said tank through said heatexchange unit and returning said brine as a spray at the top of saidmetallic tank, an air circulating fan at the upper end of said spacedvertically disposed and transversely extending partitions, and meanswhereby a major portion of the fan circulated air will pass over saidheat exchange unit when said fan is operating, said means being suchthat it will not materially interfere with a full and free convectioncirculation of air around said tank and over said heat exchange unitwhen said fan is not operating.

l0. In a refrigerated railway car having an insulated ladingaccommodating space, the combination of an ice and brine accommodatingtank mounted within said car at one end and spaced from the top, bottom,end and side walls thereof for free passage of air therearound, abulkhead defining a chamber within which said tank is disposed, saidbulkhead having an air passageway at its top communicating with theinterior of the car, a heat insulating end wall mounted in inwardlyspaced relation with respect to said bulkhead defining the limits of thelading space of the car and providing an air circulating passagewayremote from an independent of the passageway about and adjacent said iceand brine tank, said insulating end wall being disposed with its bottomedge in spaced relation with floor of the car and having an aperture atits upper edge, a fan mounted at the aperture in said end wall formaintaining an upward circulation of air through said passageway, a heatexchange unit mounted in said air circulating passageway, and a brinepump having conduit connections for circulating brine from the bottom ofsaid tank and downwardly through said heat exchange unit and dischargingsaid brine as a spray at the top of said ice and brine tank.

THORE M. ELFVING.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 927,595 Place July 13, 1909 1,040,739 Nilsson Oct. 8, 19121,093,075 Porges Apr. 14, 1914 1,822,305 Moore Sept. 8, 1931 2,115,472Sargent Apr. 26, 1938 2,187,277 Minard Jan. 11, 1940r 2,198,822 KargeApr. 30, 1940 2,267,456 Glenn Dec. 23, 1941

